Produce remap metrics only when the original metrics is present

[lahsivjar]

Current codebase will produce a zero value remapping for metrics which are missing in the originally scraped metric. Ideally, we should only produce remapped metrics if we have the values present in the original metric.

[ishleenk17]

Resolved in this issue: #36

[ishleenk17]

The issue should be fixed in a different way.
Reopening it for now.

[lahsivjar]

When we fix this, we should also log any invalid metric that is being produced as it will point to a bug on our end. This could be done in the remappedmetric/Metric.